Sheet metal bending apparatuses are well-known. Typically, sheet metal bending dies operate by supporting a workpiece between two relatively moveable die portions. For example, the workpiece may be held in a fixed position with respect to a non-moving backing portion of the die, while an anvil portion of the die is moved into contact with the workpiece to bend a portion of the workpiece about a bend line.
While such bending operations are trivial when applied to a planar workpiece, the complexity of the operation is increased substantially when the workpiece has a profiled shape prior to the bending operation. In such a case, the bend line itself is profiled, and the bend must be made in consideration of the profile of the bend line. One typical approach to bending a workpiece at a profiled bend line involves providing two or more anvil portions that are relatively moveable to a fixed backing portion of the die. These anvil portions are typically configured such that each moves along its own line of action, substantially perpendicular to the profile of the workpiece. When the two or more anvil portions first contact the workpiece during the course of the bending operation, there will typically be a gap between the two anvil portions at the location where the anvil portions contact the workpiece. This can cause some inconsistencies or quality issues in the finished workpiece. Furthermore, when the profile includes a radiused shape, the line of action of the anvil portion responsible for bending the part within the radius necessarily does not move normal to the entirety of the radiused portion.